It is believed that the prior art consists of the following publications: U.S. Pat. No. 1,042,823 (Richard, Oct. 29, 1912); U.S. Pat. No. 1,182,629 (Birnbaum, May 9, 1916); U.S. Pat. No. 5,937,524 (Hornsby, Aug. 17, 1999); and GB 756,361 (Salaman, Sep. 4, 1954).